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[Support #MMY-940696]: radar3 LDM user latencies

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  • Subject: [Support #MMY-940696]: radar3 LDM user latencies
  • Date: Tue, 13 Jun 2017 10:01:59 -0600
Holly,

> We did have one customer who has a redundant request.  Yesterday I noticed
> one pull from College Park and one from Boulder, but today I see 2 requests
> for the same data in Boulder.  One of them is delayed and my logs say
> "Terminated obsolete upstream LDM" because of this.

Don't do that. Multiple identical subscriptions from a downstream site to an
upstream site will cause the downstream LDM processes to take turns
terminating their associated upstream LDM processes.

> We failed out to
> Boulder yesterday due to these latency issues.   Dual pulling isn't
> something we have actively suggested our users do only because even though
> the data has the same name, the content could be different and will not get
> duped out because the md5 checksum is different.

> > Do all of your customers have the same REQUEST entries (i.e., for the same
> > feedtype and pattern)?

> I see a few flavors of basically the same thing, is one of these better or
> worse than the others?  We do not have any EXP data, everything is going
> out with the feed type NEXRAD3 (or FT27).
> 
> NEXRAD3, ".*"

This will get everything in the NEXRAD3 feed.

> NEXRAD3, (^wsr88d[0-9]*\.tbz2$)

The parentheses are unnecessary. This subscription is identical to the
previous one if and only if every data-product in the feed matches the
regular expression.

> NEXRAD3, "^wsr88d......tbz2

Depending on the data-product identifiers, this will receive the same
set of data-products as the previous subscription or a set that overlaps the
previous subscription.

> EXP|NEXRAD3, "^wsr88d[0-9]*\.tbz2"

This will receive the same data-products as the second subscription if and
only if not data-products exist that match the above reqular expression and
that have something after the "tbz2".

> EXP|NEXRAD3, ".*"

Because you don't have any EXP data-products, this subscription is the same
as the first one.

> > Please keep us apprised.
> 
> Will do, we will be asking one user with known issues to pull from College
> Park directly to help us troubleshoot.  Thanks for the information Steve,
> much appreciated!

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: MMY-940696
Department: Support LDM
Priority: Normal
Status: Closed
===================
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